Victoza Raises Thyroid Tumor, Pancreatitis Fears

The maker of Victoza (liraglutide) is reminding doctors of some serious side effects that may be associated with the Type II Diabetes drug – thyroid C-cell tumors and acute pancreatitis. Novo Nordisk decided to issue a â€œDear Healthcare Providerâ€ letter regarding these possible Victoza complications after an assessment showed that many primary care providers are not fully aware of the serious risks associated with the use of the drug.

Victoza was approved by the U.S. Food & Drug Administration (FDA) in January 2010. The approval of Victoza was controversial because of uncertainty about its cardiovascular risks, and animal studies showing an increased risk of thyroid cancer. As we’ve reported previously, the injectable medication acts on a hormone in the gastro-intestinal tract called glucagon-like-peptide-1 (GLP-1), which results in lower blood sugar levels. Byetta, also an injectable, is part of this class.

According to the Novo Nordisk letter to doctors, Victoza causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures in both genders of rats and mice. While it is not known if the drug causes such tumors – including medullary thyroid carcinoma – in humans, the risk can’t be ruled out. Additionally, in clinical trials studying Victoza, there were more cases of pancreatitis in patients treated with Victoza than in patients treated with comparators.

The FDA recommends that patients with thyroid nodules noted on physical examination or neck imaging obtained for other reasons should be referred to an endocrinologist for further evaluation. Although routine monitoring of serum calcitonin is of uncertain value in patients treated with Victoza, the FDA says patients should be referred to an endocrinologist for further evaluation if serum calcitonin found to be elevated.

Once patients start Victoza, and following dosage increases, they should be carefully monitored for signs of pancreatitis, the FDA said. Symptoms of pancreatitis include persistent severe abdominal pain, sometimes radiating to the back, which may or may not be accompanied by vomiting.

Worries over potential Victoza side effects, especially thyroid tumors and pancreatitis, do seem to be growing. According to the Institute for Safe Medication Practicesâ€™ (ISMP) latest â€œQuarterWatchâ€ report, an analysis of the FDAâ€™s Adverse Event Reporting database showed Victoza accounted for 70 cases of acute and chronic pancreatitis in the third quarter of 2010, and 105 cases since approval nine months earlier. This result was surpassed only by, Byetta, with 78 cases. The ISMP asserted that pre-approval testing for drugs like Victoza and Byetta is simply too short to determine whether their benefit-risk balance is favorable.

Despite such safety concerns, Victoza has become widely used with over 200,000 prescriptions dispensed in the first nine months after the FDA granted it approval, the ISMP said.